1. Field of the Art
This disclosure generally relates to methods of measuring the adequacy of a clinical sample by estimating the cell count in known fluid volumes using light scattering techniques, in particular turbidity. In another aspect, this disclosure provides machines for measuring the adequacy of a clinical sample by estimating the cell count. These machines can be used for high-throughput processing of clinical samples. In another aspect, this disclosure provides methods of determining whether a sample contains adequate material for testing of the sample to be informative.
2. Description of Related Art
In the fields of Clinical Diagnostics, Life Sciences, Forensics, and BioDefense, assurance of a sample's adequacy determination can provide several benefits to the process of sample analysis. Information content about the sample's adequacy can increase confidence in and efficacy of subsequent test results using other chemical, physical, and/or biological assays on that sample. Information content improves patient treatment since patients whose health status would be misrepresented by inadequate sample are more likely to be discovered. Avoidance of reporting an unrepresentative health result and allowing for patient re-sampling are anticipated beneficial results of sample adequacy determination. Additionally, knowledge of the sample's adequacy prior to running other sample analysis can result in time, material, and labor savings by avoiding costly testing on un-vetted inadequate samples. Thus, establishing sample assurance in screening tests on large populations where a significant number of the test results confirm an absence of analyte can add value as a confirmation that the result is representative of the original entity sampled.
Clinical samples which are being analyzed for the presence of specific cell types, viruses, bacteria or other pathogens can particularly benefit from the subject test methods as these methods will facilitate the accuracy of the test results and further enhance efficiency. One specific area that can potentially benefit from sample adequacy assurance is testing of cervical samples for HPV infection. For example, the digene HC2 High-Risk HPV DNA Test® (“HC2”) has proven to be of extreme value as a component of cervical cancer screening programs and clinical management of ASC-US cytology patients. Currently HC2 HPV DNA testing yields a high negative predictive value of approximately 99.5% for prediction of cervical lesions of CIN3 or greater. Nonetheless, laboratories and patients may desire the additional control and assurance that would be provided by measurement of sample adequacy. The opportunity to decline to test a sample determined to be inadequate may also be desired.